BSD development hasn't ended, but when was the last time Apple refreshed the userland from upstream?

Well, just a few days before, in the 10.10.5 update of OS X, Apple updated many userland utilities from upstream. This includes apache, curl and python. (https://support.apple.com/en-us/HT205031).

But you are right in general. Such update is only once in a blue moon.

Which is fair enough to gripe about, but with ports or homebrew it's hardly an issue these days.

It just goes to show how many Mac OS X users care about CLI.

I'm not sure there's much of a correlation there. Most engineers using OS X (a group that's at least as large as Linux-using engineers) use the command line on a regular basis; I think it has more to do with the fact that even a dated *nix userland has 90%+ of what the majority of engineers need.